Unretrieved task exceptions and Python 3.8 3.9

I don't know where else to comment on this, so a random wiki page will have to suffice.

Recently I noticed that keyboard interrupts (Ctrl+C) started to print tracebacks, even though the script is supposed to catch KeyboardInterrupt exceptions.

User Interrupt!
Task exception was never retrieved
future: <Task finished name='Task-110' coro=<process() done, defined at coub.py:1883> exception=KeyboardInterrupt()>
Traceback (most recent call last):
  File "coub.py", line 1970, in <module>
    main()
  File "coub.py", line 1957, in main
    attempt_process(coubs)
  File "coub.py", line 1922, in attempt_process
    asyncio.run(process(coubs), debug=False)
  File "/usr/lib64/python3.8/asyncio/runners.py", line 46, in run
    _cancel_all_tasks(loop)
  File "/usr/lib64/python3.8/asyncio/runners.py", line 61, in _cancel_all_tasks
    loop.run_until_complete(
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 603, in run_until_complete
    self.run_forever()
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 570, in run_forever
    self._run_once()
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 1859, in _run_once
    handle._run()
  File "/usr/lib64/python3.8/asyncio/events.py", line 81, in _run
    self._context.run(self._callback, *self._args)
  File "coub.py", line 1891, in process
    await asyncio.gather(*tasks)
  File "/usr/lib64/python3.8/asyncio/runners.py", line 43, in run
    return loop.run_until_complete(main)
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 603, in run_until_complete
    self.run_forever()
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 570, in run_forever
    self._run_once()
  File "/usr/lib64/python3.8/asyncio/base_events.py", line 1859, in _run_once
    handle._run()
  File "/usr/lib64/python3.8/asyncio/events.py", line 81, in _run
    self._context.run(self._callback, *self._args)
  File "coub.py", line 1074, in process
    self.check_existence()
  File "coub.py", line 910, in check_existence
    if old_file and not overwrite(old_file):
  File "coub.py", line 1701, in overwrite
    answer = input("#? ")
KeyboardInterrupt

This is such a typical traceback. Important to note is that User Interrupt! is still being printed.

Initially I thought it might have something to do with this asyncio issue, but then it should've happened in the past as well.

After some more testing I realized that the issue only occurs when I use Python 3.8 or Python 3.9, while it works fine with Python 3.7.

I don't know enough about asyncio's underlying implementation to understand what change caused this new behavior (perhaps it has something to do with the changed base class for asyncio.CancelledError, but that's only a vague guess at best). Likewise I have no idea how to fix it.

So for now I can do nothing but acknowledge this problem.